blob: 45e76e5bc1ea864b9c224c3e6749cd50a205e996 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
|
.. -*- coding: utf-8; mode: rst -*-
.. _media_ioc_enum_entities:
*****************************
ioctl MEDIA_IOC_ENUM_ENTITIES
*****************************
Name
====
MEDIA_IOC_ENUM_ENTITIES - Enumerate entities and their properties
Synopsis
========
.. c:function:: int ioctl( int fd, MEDIA_IOC_ENUM_ENTITIES, struct media_entity_desc *argp )
:name: MEDIA_IOC_ENUM_ENTITIES
Arguments
=========
``fd``
File descriptor returned by :ref:`open() <media-func-open>`.
``argp``
Description
===========
To query the attributes of an entity, applications set the id field of a
struct :c:type:`media_entity_desc` structure and
call the MEDIA_IOC_ENUM_ENTITIES ioctl with a pointer to this
structure. The driver fills the rest of the structure or returns an
EINVAL error code when the id is invalid.
.. _media-ent-id-flag-next:
Entities can be enumerated by or'ing the id with the
``MEDIA_ENT_ID_FLAG_NEXT`` flag. The driver will return information
about the entity with the smallest id strictly larger than the requested
one ('next entity'), or the ``EINVAL`` error code if there is none.
Entity IDs can be non-contiguous. Applications must *not* try to
enumerate entities by calling MEDIA_IOC_ENUM_ENTITIES with increasing
id's until they get an error.
.. c:type:: media_entity_desc
.. tabularcolumns:: |p{1.5cm}|p{1.7cm}|p{1.6cm}|p{1.5cm}|p{11.2cm}|
.. flat-table:: struct media_entity_desc
:header-rows: 0
:stub-columns: 0
:widths: 1 1 1 1 8
- .. row 1
- __u32
- ``id``
-
-
- Entity id, set by the application. When the id is or'ed with
``MEDIA_ENT_ID_FLAG_NEXT``, the driver clears the flag and returns
the first entity with a larger id.
- .. row 2
- char
- ``name``\ [32]
-
-
- Entity name as an UTF-8 NULL-terminated string.
- .. row 3
- __u32
- ``type``
-
-
- Entity type, see :ref:`media-entity-type` for details.
- .. row 4
- __u32
- ``revision``
-
-
- Entity revision. Always zero (obsolete)
- .. row 5
- __u32
- ``flags``
-
-
- Entity flags, see :ref:`media-entity-flag` for details.
- .. row 6
- __u32
- ``group_id``
-
-
- Entity group ID. Always zero (obsolete)
- .. row 7
- __u16
- ``pads``
-
-
- Number of pads
- .. row 8
- __u16
- ``links``
-
-
- Total number of outbound links. Inbound links are not counted in
this field.
- .. row 9
- __u32
- ``reserved[4]``
-
-
- Reserved for future extensions. Drivers and applications must set
the array to zero.
- .. row 10
- union
- .. row 11
-
- struct
- ``dev``
-
- Valid for (sub-)devices that create a single device node.
- .. row 12
-
-
- __u32
- ``major``
- Device node major number.
- .. row 13
-
-
- __u32
- ``minor``
- Device node minor number.
- .. row 14
-
- __u8
- ``raw``\ [184]
-
-
Return Value
============
On success 0 is returned, on error -1 and the ``errno`` variable is set
appropriately. The generic error codes are described at the
:ref:`Generic Error Codes <gen-errors>` chapter.
EINVAL
The struct :c:type:`media_entity_desc` ``id``
references a non-existing entity.
|
